Apparatus for assembling piano cases



Oct. 3, 1939. J. sAuERLAND 2,174,570

APBARATUS Fon AssEMBLING PIANO .CASESA Filed oct. 30, 1936ztxsheets-sheet 1 ATTORNEY .5

Oct. 3, 1939. JJSAUERLAND 2,174,570

APPARATUS FOR ASSEMBLlNG PIANOCASES Filed oct. 5o, 195e 2 sheets-sheet 2Patented Oct. 3, 1939 UNITED STATES PATENT `OFFICE.

Joseph Sauerland, West New York, N. J assignor to Hardman, Peck andCompany, New York,

N. Y., a corporation of New York Application October 30, 1936, SerialNo. 108,324

1 Claim.

This invention relates to the manufacture of piano cases and moreparticularly to cases for so-called miniature pianos, that is to say,pianos of the upright type having the keyboard at or 5 near the top of'the instrument.

The major parts of the piano case are the back assembly, which includesthe wooden framework, the sounding board and the metal string frame` andthe two sides, These sides are of a hollow, box-like construction,serving not only as parts of the cabinet but also as sound chambers forthe improvement of the tone of the instrument. An object of theinvention is to provide a piano case of the type described which shallbe of simple construction yet strong, and shall have the desiredacoustic characteristics. 'I'he back assembly an'd the sides. areconstructed as separate units and a further object of this invention isto provide a method of and apparatus for assembling them togetherquickly, accurately and with a minimum of labor. This invention makes itpossible for one man to perform all of the operations of assemblingwithout assistance, as will more fully appear hereinafter.

Other objects and advantages will be apparent from the 'followingdetailed description of the present preferred embodiment of theinvention, taken in connection with the drawings, in which:

Fig. 1 shows in perspective the assembled back and sides of a piano casefor a miniature piano;

Fig. 2 is a side view showing the apparatus used for assembling the casewith the table in vertical position and the back of the piano case inplace thereon;

Fig. 3 is a view corresponding to Fig. 2, but With the table inhorizontal position and showing the sides of the piano case in place;

Fig. 4 is a top plan view, partly in section, of the table with the backand sides of the piano case in position thereon;

Fig. 5 is a cross-section taken on the line 5-5 of Fig. 4;

Fig. 6 is a detailed cross-section showing the means for securing theside to the back of the piano, and

Fig. 7 is a view taken on the line 'I-I of Fig. 6.

Figs. 8 and 9 correspond with Figs. 6 and '7, respectively, but show theposition of the fastening means after relative movement of the back andside into locking position.

The construction of the piano case will be described first, followed bydescriptionsl of the apparatus used forassembling it and the method ofassembling.

(Cl. 14A-288) Referring to Fig. 1, it will be seen that the main partsof the piano case are the back assembly I and the sides I2 and I4. Manydetailed parts such as strings, bridges, tuning pins, etc., are omittedfor greater clarity, being no part of the invention. The back assemblyII] (see Figs. 4 and includes the iron string frame II, which is of suchrigidity and strength as to require no support from'` the wood parts. Tothe frame II a rather light, rectangular wooden frame structure I3 issecured by screws (not shown), in which is held the sounding board I3.The frame Il is provided at its two lower corners with short angularextensions 49 and midway of its sides with flat lugs or brackets 48,these extensions and brackets being provided with holes. for screws.

The sides I2 and I4, it will be noted, are hollow and are built up ofthe base pieces 42, inner panels 44, outer panels 45, front pieces 46,tops and bottoms. The panels are preferably of plywood. The box-likeconstruction of these sides greatly improves the tone of the piano asthe sides act as sound chambers or resonators for the vibrationstransmitted to them from the back.

The sides, after being built, are prepared for assembling by cuttinginthem the openings illustrated in Figs. 6-9, the locations of which maybe seen in Figs. 4 and 5.l These openings are generally in the shope ofa keyhole and consist of a round hole or boring 34 into which opens anelongated slot 35. The hole 34 is of such a size as to receive freelythe head 36 of a large flathead screw. The slot 35 is of a size toreceive freely the shank 38 of the screw. The sides may be completelyfinished with varnish or lacquer prior to assembling..

It will, of course, be understood that after the case has reached thestage shown in Fig. 1, the piano is completed by installing the action,keyboard, top, baseboard, front, etc. The present invention does notrelate to any of these parts or subsequent operations.

Referring to Figs. 2 5, the apparatus used in assembling the piano caseconsists of a standard having a base I5, rear uprights: I6 and frontuprights I8. Secured to the front uprights I8 by suitable pivots I9 isthe table 20 provided with bracket members 2l which are attached to thepivots I9. The table 20 is so mounted that it will remain either in thevertical or horizontal position and in the latter position, as shown inFig, 3, it rests upon the rear uprights I6.

On the top of the table, as is best shown in Figs. 4 and 5, clampingmeans are provided for applying pressure to the units in assembling themconsisting of the stationary block 22 at the left and the bevelled wedgeblocks 24 and 25 at the right. A pair of wedges 26 and 28 cooperate withthe wedge blocks to clamp the parts. Secured to the lower edge of thetable are a pair of metal stops 29 and 3U which are preferably sunk intothe top of the table so as to have their body portions flush with thesurface. On the opposite side of the table, and preferably mounted on atongue 3| provided for that purpose, is a screw clamp 32 adapted topress against the upper side of the back I0 and force it toward thestops 29 and 3U.

Figs. 6 and 7 show the position of the sides relative to the back andfastening screws during the first step of the assembly. After being thuspositioned and while the sides are held securely against the edges ofthe back by the -wedges 26 and 28, the back and sides are moved relativeto one another so that the screws move into the I position shown inFigs. 8 and 9. As shown in n little effort.

those figures, this movement causes the head 36 of the screw to cut agroove 39 into the wood surrounding the slot 35, which results insecurely locking the sides to the back.

The operation of assembling the piano case is as follows: The table 20is placed in the vertical position shown in Fig. 2, so as to make itpossible to place the back assembly against the table, requiring it tobev lifted only a few inches from the floor, as can easily be done byone man. Initial engagement of the rear edge of the back assembly withthe stops 29, 3U is accomplished by tilting said assembly away from `thetable 20 on the extensions 49 of the string frame, which elevates therear edge to the level of the stops 29, 30, onto which it can be movedby sliding it along the floor. Tilting the back assembly toward thetable then lifts it off the oor with expenditure of very In thisoperation, the back is rested on the stops 29 and 30 and heldtemporarily against the table 20 by the clamp 32. The table isthenturned into the horizontal position shown in Fig. 3. The clamp 32 isthen released and the I back is` moved away from the stops 29 and 30 ashort distance, as shown in Fig. 4. The positions for the four screws 36are marked on the back, holes drilled, and the screws are inserted. Toenable this to be done easily two holes 40 are cut in the stationaryblock 22 and similar holes 4I are cut in the wedge blocks 24 and 25,opposite the screw positions through which drills and screw drivers maybe inserted. The sides .are then painted with glue on the surfaces whichwill abut the back, and the sides are put in position with thescrew-heads 36 inserted into the holes 34, as

shown in Figs. 6 and '7. 'I'he bottoms of the sides rest against thestops 29 and 30 and, as is obvious, the back is above these stops by thedistance through which the screws 36 will travel from their initial totheir fastening positions, as shown resp-ectively in Figs. 6 and 8.

Fillets 43 of smooth wood are put in place against the sides to protecttheir finish and the wedge blocks 26 and 28 are then driven intoposition to clamp the sides securely against the back. While the partsare maintained under this clamping pressure the screw clamp 32 is turnedto force the back toward the stops 29 and 3U until it engages them.During this operation the glue, which is still wet,. serves as alubricant. The screw heads cutting into the wood of the sides duringthis operation lock the sides securely to the back.

vDue to slight variations in the size or shape of the string frame,which inevitably result from the fact that it is a casting, the stringframe is made of such a size that it does not quite reach the sides l2and I4. After the operations described above are completed and after thesides have been squared up, wooden shims are inserted to fill the spacesbetween the sides and the lugs 48 and extensions 49, after which thesides are securely screwed to these lugs and extensions.

The piano case may then immediately be removed from the table, althoughthe glue has not yet dried, as the sides will be securely heldacculrately in position on the back assembly. The case is removed fromthe table by returning it to its vertical position as shown in Fig. 2,releasing the clamp 32 and sliding the case off onto the floor.

It will be seen that great economy of time is effected by not having towait for the glue to dry before the further operations of assembling acomplete piano are proceeded with. Further -economy is effected byreason of the fact that the entire assembly may be done by one manwithout assistance. Moreover, he initially fastens both sides in placeby a single movement between the back and sides produced by the screwclamp 32.

The construction of the piano case described above is the subject of mycopending application, Serial No. 184,169, filed January 10, 1938.

The foregoing description pertains only to what is now considered thepreferred embodiment of the invention and it is obvious that manychanges in detail might be made therein. For example, the screw clamp 32might be replaced by any means performing the equivalent function, suchas an hydraulic jack or a device working from pneumatic pressure.Similarly, the wedges might be replaced by any devices performing theequivalent function. While flat-head screws are the means disclosed forfastening the sides to the back, any suitable fastening member may beused. Instead of using a fastening which will cut its own groove afastening not capable of so doing might be used in conjunction with agroove preformed to receive it.

What is claimed is:

Apparatus for use in joining the sides to the back assembly in themaking of an upright piano wherein the sides are locked to the back byfastenings rendered operative by relative sliding movement between theback and the sides, comprising a table upon which the sides and backassembly are supported while being locked together, a support upon whichthe table is tiltable into either a horizontal or vertical position andso arranged that the table will be maintained in either position bygravity and when in the vertical position will have an edge adjacent theiioor, outwardly extending stop means carried by the table adjacent theedge which is lowermost-when the table is in vertical position wherebythe back assembly may be engaged by said means while still partiallyresting on the floor, clamping means secured to the table in opposingrelation to said stop means and adapted to temporarily engage the backassembly to hold it while the table is moved into horizontal positionand to forcibly move said assembly toward said stop means duringthevjoining operation, means for clamping the sides against the backcooperating with said stop means to retain the sides in fixed positionswhile the back assembly is moved into abutting engagement with said stopmeans under the action of the first-mentioned clamping means.

JOSEPH SAUERLAND.

